Alert archive / Colorado / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 186, NWS Denver/Boulder, CO

July 27, 2009Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 27, 2009, 3:28 PM MDT for Weld County, Colorado. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 27, 2009, 3:28 PM MDT (21:28 UTC)
Expired: Jul 27, 2009, 4:17 PM MDT
In force: 49 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 75 km from the middle of the area, began a volume at 21:30 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 27, 2:55 PM MDT, 33 minutes earlier.

Area forecast discussion, Jul 27, 2:55 PM MDT, 33 minutes before

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Hazardous weather outlook, Jul 27, 11:11 AM MDT, 4 hours 17 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER CO
1111 AM MDT MON JUL 27 2009

COZ030>051-281200-
JACKSON COUNTY BELOW 9000 FEET-WEST JACKSON AND WEST GRAND
COUNTIES ABOVE 9000 FEET-GRAND AND SUMMIT COUNTIES BELOW 9000
FEET-SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-SOUTH AND SOUTHEAST
GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/GILPIN/CLEAR CREEK/
SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE 9000 FEET-LARIMER AND
BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET-JEFFERSON AND WEST
DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR CREEK/NORTHEAST PARK
COUNTIES BELOW 9000 FEET-CENTRAL AND SOUTHEAST PARK COUNTY-LARIMER
COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-BOULDER AND JEFFERSON
COUNTIES BELOW 6000 FEET/WEST BROOMFIELD COUNTY-NORTH DOUGLAS
COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND ARAPAHOE COUNTIES/
EAST BROOMFIELD COUNTY-ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES
ABOVE 6000 FEET-NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD
COUNTY-MORGAN COUNTY-CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES-
NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN
COUNTY-SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN
COUNTY-LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS
COUNTY-
1111 AM MDT MON JUL 27 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

.DAY ONE...TODAY AND TONIGHT

A COLD FRONT COMBINED WITH AN UPPER LEVEL DISTURBANCE WILL PRODUCE
WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION BY LATE THIS
AFTERNOON AND TONIGHT.  THE GREATEST THREAT FROM THE STORMS WILL BE
HEAVY RAIN. THE BEST CHANCE FOR HEAVY RAIN WILL BE OVER THE
NORTHEAST PLAINS WHERE 1 TO 2 INCHES OF RAIN COULD FALL WITH A
STRONG THUNDERSTORM. GUSTY WINDS AND SMALL HAIL MAY ALSO ACCOMPANY
STRONGER STORMS. ALTHOUGH THERE IS A THREAT OF SEVERE THUNDERSTORMS
...THE OVERALL THREAT WILL BE LOW.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

TUESDAY WILL BE COOL AND SHOWERY ACROSS THE NORTHEAST PLAINS AND
FOOTHILLS AS THE UPPER LEVEL DISTURBANCE AND COLD FRONT REMAINS OVER
THE STATE.  HIGH COUNTRY LOCATIONS WILL ESCAPE THIS SURGE OF COOL
AIR...BUT DAYTIME HEATING WILL PRODUCE THE USUAL ROUND OF AFTERNOON
AND EVENING THUNDERSTORMS.

ANOTHER WEATHER DISTURBANCE AND COLD FRONT WILL MOVE ACROSS THE
REGION ON WEDNESDAY PRODUCING ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS...AS WELL AS UNSEASONABLY COOL UPSLOPE CONDITIONS
THROUGH THURSDAY.  SOMEWHAT DRIER AND WARMER CONDITIONS ARE EXPECTED
TO RETURN TO THE AREA BY FRIDAY AND CONTINUE THROUGH THE WEEKEND
WITH HIGH PRESSURE BUILDING IN FROM THE WEST.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

COOPER/DANKERS

In the hours before

Special weather statement, Jul 27, 1:15 PM MDT, 2 hours 13 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
115 PM MDT MON JUL 27 2009

COZ035-038-271945-
LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY CO-
LARIMER AND BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET CO-
115 PM MDT MON JUL 27 2009

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SIGNIFICANT
WEATHER ADVISORY FOR

  NORTHEASTERN LARIMER COUNTY
  NORTHWESTERN WELD COUNTY

AT 115 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND WIND GUSTS TO
AROUND 50 MPH.  THIS STORM WAS LOCATED OVER INTERSTATE 25 JUST WEST
OF CARR...OR ABOUT 24 MILES NORTHEAST OF FORT COLLINS. THIS STORM
WAS NEARLY STATIONARY.

LOCATIONS IN THE ADVISORY INCLUDE BUT ARE NOT LIMITED TO ROCKPORT...
NUNN...NATURAL FORT REST AREA AND CARR.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM WILL PRODUCE DANGEROUS CLOUD-TO-GROUND LIGHTNING. IF
OUTDOORS...STAY AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES AND
MOVE INDOORS IF POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND
DOORS AND AVOID USING LAND LINE TELEPHONES UNLESS IT IS AN EMERGENCY.
TRY TO UNPLUG UNNECESSARY ELECTRICAL APPLIANCES BEFORE THE
THUNDERSTORM APPROACHES. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE
IN DANGER OF BEING STRUCK BY LIGHTNING.

&&

LAT...LON 4092 10455 4063 10478 4086 10514 4100 10502
      4100 10499
TIME...MOT...LOC 1915Z 180DEG 0KT 4088 10491

BARJENBRUCH

Local storm report, Jul 27, 1:36 PM MDT, 1 hour 52 minutes before

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Local storm report, Jul 27, 3:15 PM MDT, 13 minutes before

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The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 27, 1:15 PM MDT	Special Weather Statement	BOU	Weld	30 min
Jul 27, 2:28 PM MDT	Severe Thunderstorm Warning	BOU	Weld	62 min
Jul 27, 4:08 PM MDT	Severe Thunderstorm Warning	BOU	Arapahoe, Denver	45 min
Jul 27, 4:15 PM MDT	Severe Thunderstorm Warning	BOU	Douglas, Elbert	39 min
Jul 27, 5:06 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	54 min
Jul 27, 5:23 PM MDT	Tornado Warning	BOU	Elbert, Lincoln	37 min
Jul 27, 5:49 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	40 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2009 Every severe thunderstorm warning in 2009

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.